Little Big Man is a fun, picaresque western with some fine visual sequences and plenty of good acting. But it's a major step down from the book, one of the finest American novels of the '60s. The difference is in the handling of the characters. The movie presents Custer, Wild Bill Hickok, Rev. Pendergast and his wife, the patent medicine seller, and the rest as comic "turns," not as full-fledged people in their own right. Maybe this is how Penn, with his theatrical background, instinctively saw the material, and it gives the movie too much of a Blazing Saddles feel. The script (or perhaps what Penn uses of it) boils much of the dialog down into one-liners (doubtless, the task of condensing such a sprawling story into a movie of less than three hours didn't help). Even Chief Dan George, as Old Lodge Skins, the best developed character here, often comes across as merely a lovable schlemiel. Much of it's funny, but it doesn't cut very deep.
The book is more human, giving each character Jack encounters three dimensions and avoiding the trap of rendering any of them either all good or all bad. The moment in Penn's film that best evoke the book is the scene where Custer catches Jack approaching to kill him and instead of killing his stalker, lets him go. Throughout this wonderful novel, characters do unexpected things that seem at first to be totally out of character, and thus serve to remind us of the complexity of human beings. As someone suggests here, the film may intend to say something about the random, unpredictable nature of the universe. The novel does something a lot more difficult and down-to-earth: It reminds us that it takes a lifetime to know even a few of our fellow humans. And especially for Jack, who has to navigate two distinct cultures.
So if you liked the movie, by all means read the book. You'll finish it loving this tall tale way more.
